Work holder



June 16, 1953 J. G. ZUMMACH WORK HOLDER 2 Sheets-Sheet l v Filed Sept. l, 1949 ATTORNEYS.

x ////////A m June 16, 1953 J. G. ZUMMACH WORK HOLDER Fiied Sept. 1949 2' Sheets-Sheet 2 INVENTOR.'

ATORNEYS.

Patentec June 16, 1953 anen WORK Homeri' John G. Z'nmach, Brownsville, Tex., assignor to Young Radiator Company, Racine, Wis., a corporation of Wisconsin Application September 1, 1949, Serial No.'113,5'67

7 Claims.

The main objects of this inventic n are to provide an improved form oi work holder for machines where the work is advanced for action .thereon by a tool; to provide. a, work holder of this kind having improved means for simultaneously clamping the work to the holder and connecting the 'holder to the'work-advancing nechanism; to provide improved means for normally retracting the 'aforesaid means; and to provide an improved work holder of this kind which is economical to manufacture and effective in operation.

In the accompanying drawings:

Fig. 1 is a side elevation of a machine (intermediate 'and end portions being omitted) whereon is arranged a work holder constructed in accordance with this invention. The View shows the head stock and the power' unit whereby the work holder is advanced toward the tool-supporting head stockand the work 'is simultaneously rotated; v i v Fig, 2 is an -enlarged cross sectional View of this improved work holder, taken on the plane of the line 2-2 of Fig- 1;

Fig. 3 is a longitudinal sectional elevation-al view of the same, taken on the plane of the line 3-3 of Fig. 2; and

Fig. 4 is a partly-sectional, partly-elevational detail taken on the line 4-4 of Fig. 3.

A machine 5, for use with which this improved work holder 5 has been designed, comprises a framework 'I supporting a pair of horizontallydisposed, spaced channel bars 8 constituting the machine 'bed whereon are mounted the aforesaid work holder 6 and a tool-'supporting head stock 9. A combined lead-screw and driVe-shat ID is j ournaled between the channel bars'i and extends from the rear end of the framework 'l up to a, point adjacent the head stock 9,. This combination lead-'screw and drve-shaft Hi is driven by a motor 'l l connected thereto through themedium of conven'tional reduction-gear and speed-control `mechanism 12.

' This 'improved form of work holder '6 'comprises a'h'ousing l3 mounted for movement on the 'chan nel'bars 8 and supporting a rotating 'work cl'amp !4 and a shiftable feed-screw connecting-member !5 which are simultaneously actuatedby a cam v mechanism 16 'to grip ;a piece of work'fl '(see 1) 'and connect-,the workholder -6 with the combination feed-screw 'and drive-sh'aft o so 'as to advance the 'work 11 toward the 'head stock '9. A tool (not shown) oi a' character suitable for performing 'the desired operation on the Work 'l 'l is mountablezon' the head stocks. v v ;The work-:holderhousng 13 :is in. the form -o'f an arcuate-shaped, hollow casting or .base having the lateral portions !8 thereof recessed to provide races e f-or the rollers 20 which support the work holder 6 for travel along the channel bars 8. Front and rear end plates or caps 21 and 22 are secured to the axial ends of the housing !3 to complete an enclosure for the work clamp l4 and for the cam mechanism IE.

The workclamp |4 comprises a spindle 23 journaled on bearings 24 and driven by gearing 25, wherein is arranged a collet 26 connected to an axially-shiftablesleeve 2? for movement into and out of contracting engagenent with an internallytapered bushing 28.

The spindle 23 mounts a, collar .29 which is connected to the sleeve 21 by a pin 30 extending through a slot 3l.

The bearings 24 here shown are of the type.

The gearing 2-5 comprises a gear 32 connected to a pinion 33 through the medium of an idle gear 34. The gear 32 is journaled on. the housing 13 and suitably splined to the combination leadscrew' and drive-shaftltso that it rotateswith, as it moves along, theshaft lil. The pinion 33 is keyed to the end of the spindle %and held in place by a nut 35. i

The collet'ZG is of, more' or less standard construction being .provided With axially-disposed Sli'ts 36 'which permit the several sections of the exteriorly-tapered end to be drawn together to clamp the work within `the collet, when the'collet is drawn inwardly against the tapered bore 37' of the bushing 28.

The sleeve 21 is connected at its outer end to the collet 26, as shown at 38, and is normally urged by aspring 39, interposed between the inner end of'the sleeve 21 and a spindle shoulder 40, to retract the collet 26 from the tapered bore 31 of the bushing 28 so that the collet is normally expanded 'to receive a piece of work H.

The work-holder advancing means |5 comprises a block 41, the uppe-'end of which is shaped to roller slide between the lateral side parts !8 of the Springs' 45, interposed be-.

the right depression of the block ll, under the action of the cam mechanism 16 to ensure the proper contact of the cap 42 with the threaded shaft [0.

The cam mechanism 16 comprises an eccentric 48, a cam ring 49, a thrust bearing 50, actuating pins 51, and a lever 52 mounting a knob 53 on its outer end.

The eccentric 48 is rotatably mounted on the spindle 23 so that a slightly less than ninetydegree rotation Will shift the block 41 of the work-advancing means l against the action of the springs 45 to bring the threaded cap 42 into meshing engagement with the combination leadscrew and drive-shaft 16.

The cam ring 49 is provided with a number of cam surfaces 54 (see Fig. 4) in the face thereof;

which is opposed to the eccentric 48. Between these cam surfaces 54 and the thrust bearing 56 the several pins 5| are interposed. A bolt 55 extending through a slot in the housing l3 and secured to the cam ring 49 permits an annular adjustment of the ring 49 to ensure the correct amount of retraction of the sleeve 21 to properly bind the work il in the collet 26.

The thrust bearing 56, preferably a roller bearing, is mounted on the spindle 23 adjacent the collar 32.

The pins 5! are slidably mounted in pockets in the eccentric 48. Their inner rounded ends abut the cam surfaces 54 on the ring 49 and With their rear ends abut the thrust bearing 50. Thus, when the eccentric 48 is rotated to depress the block 4l to connect the threaded cap 42 with the combination lead-screw and drive-shaft o the pins 5! are forced by the cam surfaces 54 to shift the sleeve 27 against the action of the spring 39, thereby drawing the collet 26 inwardly and causing the tapered bore 3'! on the bushing 28 to bind the collet 26 to a piece of Work l'l.

The lever 52 is connected to the eccentric 48 and extends out through a slot 56 in the housing [3 which permits an angular movement of the eccentric 48 between the extreme positions indicated by the dotted and full Outline shownrin Fig. 2.

The work holder, herein shown and described, is used in the following manner:

Normally, the lever 52 would be shifted to the left of Fig. 2 to position the eccentric 48 so as to permit the spring 39 to retract the collet 26 from the tapered bore 31 of the bushing 28 and permit the springs 45 to retract the cap 42 of the block 4| from meshing engagement With the combination lead-screw and drive-shaft lil. A piece of work I'd thereupon could be inserted, generally from the rear end of the spindle 23, through the collet 26 and into operative relationship with the head stock 9. The work l'l being positioned for proper action of the forming tool on the head stock 9, the lever 52 would be swung into the position shown in full lines in Fig. 2. v This would rotate the eccentric 48, causing a simultaneous del'l. whenthe forming operation on the work re-l quires it. When the Work holder has moved up to the head stock the lever 52 is manually shifted in the o posite direction whereupon the reverse rotation of the eccentric 48'retracts the cap 42, on the block I5, from engagement with the shaft [0 and releases the collet 26 from the work IT. Thereupon the work holder 6 is free tobe shifted to the opposite end of the framework 2 for a repetition of the above described operation.

Variations and modifications in the details of structure and arrangement of the parts may be resorted to within the spirit and coverage of the appended claims.

I claim:

1. A device of the class described comprising, a supporting rame, a housing mounted to traverse said frame, a threaded shaft journaled on said frame, means for rotating said shaft, an axiallyshiftable collet mounted on said housing, a radially-shiftable screw-engaging member mounted on said housing and adapted for meshing engagement with said shaft, an eccentric mounted on said housing concentrically with said collet and Contacting said member so that the rotation of said eccentric shifts said member radially of said shaft into meshing engagement therewith, a collar connected to said collet, a cam surface on said housing, means axially-shiftable on said eccentric and interposed between said cam surface and said collar whereby a rotation of said eccentric causes an axial shifting of said collet for gripping a piece of work to said housing simultaneously with the shifting of said member to engage said shaft, and a manually operable lever connected to said eccentric for rotating the same.

2. A device of the class described comprising, a supporting rame, a housing mounted to traverse said, rame, a threaded shaft journaled on said irame, means for rotating said shaft, an axiallyshiftable collet mounted on said housing, a radially-shiftable screW-engaging member mounted on said housing and adapted for meshing engagement with said shaft, an eccentric mounted on said housing conc'entrically of said collet and engaging said member so that the rotation of said eccentric efiects radial shifting of said member to operatively engage said shaft, a thrust bearing connected to said collet, a plurality of cam surfaces ormed on the face of said housing opposing said eccentric, pins axially-shiftable on said eccentric and interposed between said thrust bearing and said cam surface whereby the rotation of said eccentric efiects an axial shifting of said collet to grip a piece of work thereto simultaneously with the shifting of said member to engage said shaft, and a manually operable lever connected to shiftsaid eccentric.

3. A device of the class described comprising, a supporting frame, a housing mounted to traverse said iframe, a threaded shaft journaled on said frame, means for rotating said shaft, an axially-shiftable collet mounted on said housing, a radially-shiftable screw-engaging member mounted on said housing and adapted for meshing engagement with said shaft, resilient means normally retracting said collet from engagement with a piece of work, other resilient means normally retracting said screw-engaging member,- a cam element rotatably mounted on said hous- 'ing having parts thereof adapted to actuate said collet and said member Whereby the rotation of said cam element simultaneously shifts said collet against the action of said first-mentioned ,resilient means to engage a piece of work and shifts saidimember against the action ofsaid other resilient meansinto meshing engagement with said threaded shaft, and a manually operable lever connected to actuate said cam element. i

4. A device of the 'class described comprising, a supporting frame, a housing mounted to traverse said frame, a lead-screw shaft journaled on said frame, means for rotating said shaft, a spindle journaled on said housing, gearing connecting said spindle with said shaft to eifect the rotation of said spindle, a sleeve slidably mounted in said spindle, a collet connected'to said sleeve and movable into and out of contact with a tapered bore on said spindle, a collar mounted for axial movement on said spindle, means connecting said collar with said sleeve to cause said sleeve and collar to move in unison, a radiallyu shiftable lead-screw engaging member mounted on said housing, an eccentric mounted on said spindle and engaging said member so that the rotation of said eccentric effects a shifting of said member radially of said spindle into meshing engagement with said lead-screw shaft, a thrust bearing mountedon said spindle in abutment With said collar, a plurality of cam surfaces formed on the face of said housing opposing said eccentric, pins axially-shiftable on said eccentric and interposed between said thrust bearing and said cam surfaces so that therotation of said eccentric effects .an axial shifting of said sleeve to cause said collet to grip a piece of work theret simultaneously with the shifting of said member into meshing engagement with said lead-screw shaft, and a manually operable lever connected to Shift said eccentric. y g 5. A device of the `class described "comprising, a supporting frame, a housing mounted'to traverse said frame, a lead-screw shaft journaled on said frame, means for rotating said shaft, a spindle journaled on said housing, gearing connecting said spindle with said shaft to effect the rotation of said spindle, a, sleeve slidably mounted in said spindle, a collet -connected to said sleeve and movabie into and out of contact with a tapered bore on said spindle, a collar mounted for axial movement on said spindle, means connecting said collar with said sleeve to ,cause said sleeve and collar to move in unison, a radiallyshiftable lead-screw engaging member mounted on said housing, an eccentric mounted on said spindle and engaging said member'so that the rotation of said eccentric efiects a shifting of said member radially of said spindle into meshing engagement with said lead-screw shaft, a thrust hearing mounted on said spindle in abutment with said collar, a cam ring mounted on said housing concentrically of said spindle, a plurality of cam surfaces formed on the face of said ring opposing said eccentric, pins axially-shiftable on said eccentric and interposed between said' thrust hearing and said cam surfaces so that the rotation of said eccentric effects an axial shifting of said sleeve to cause said collet to grip a piece of work thereto simultaneously With the shifting of said member into meshing engagement with said lead-screw shaft, means for rotatably adjusting said cam ring on said spindle, and-a manually operable lever connected to shift said eccentric.

6. A device of the class described comprising, a supporting frame, a housing mounted to traverse said frame, housing-advancing means associated with said frame, a clamp on said housing shiftable into and out of position to secure a piece of work to said housing, a, member on said housing shiftable into and out of position to engage said housing-advancing means, cam surfaces axially and radially disposed with respect to said clamp and member, means including a rotatably-mounted element interposed between said cam surfaces whereby the rotation of said element simultaneously shifts said clamp into engagement with a piece of work and shifts said member into engagement with said housingadvancing means, and a manually operable lever connected to actuate said cam element.

7. A device of the class described comprising, a supporting frame a housing mounted to traverse said frame, athreaded shaft journaled on said frame, means for rotating said shaft, an axially-shiftable collet mounted on said housing, a radially-shiftabie screW-engaging member mounted on said housing and adapted for meshing engagement with said shaft, cam surfaces axially and radially disposed withrespect to said shaft and collet, means including a rotatablymounted element interposed between said cam surfaces whereby therotation of said element simultaneously shifts said collet to grip a piece of Work and shifts said member into meshing engagement with said threaded shaft, and a manually oper'able lever connected to actuate said element.

JOHN G. ZUMMAC'H.

References Cited in the file of this patent UNITED STATES PATENTS Number V Name Date 725379* schellenbach Apr. 21, 1903 i 811, 111 Koons Jan. 30, 1906 v 826,835 Crump et al July 24, 1906 1,019,542 Smith Mar. 5, 1912 1,140,463 Jung May 25, 1915 1,241,258 Hawthorne sept. 25, 1917 2,319,963 Wilson et al. May 25, 1943 2343914: Lloyd Mar. 14, 1944 2,376,476 g Chatelain May 22, 1945 

